use an input amplifier
You will have to convert from differential input to single ended with an op amp. Us the classical method where the two inputs are connected to the inputs of the op amp with resistors and there are resistors from the - input to the output and from the + input to ground. Make all 4 of them the same value. To go back to differential output, use the filter output as one side and an inverting gain of -1 amplifier circuit to make the other output.
At this frequency range, the passive filter components start becoming more ideal (less resistance) and you sould consider such filters. To make a differential filter take the single ended one and copy the series parts on both lines and put half the value of the shunt parts between the lines.
What is amusing is that filter theory was originally invented by people working for telephone company laboratories and the filters were differential at the beginning.